Capt. Mooron wrote:
No John.. I believe Doug's premise is that a properly engineered vang can
equal the capacity of a topping lift... that I dispute.

And you're wrong.

Allow me to put to you 2 separate scenarios... a rigid vang on a 20 footer
and a rigid vang on a 50 footer. Now... on the 20 footer it's obvious the
weight of a man on the end of the boom would tax the rigid vang....

Not necessarily. It depends entirely on how the rig is built.

You assume that the rig, particularly the boom, and the vang must be
weak. It ain't so.

I suspect that you cannot envision a box section boom, or a custom
section boom. Have you ever seen a boat where the boom was not the same
extruded section as the mast? They exist.

Furthermore, I suspect you have little to no experience with fractional
rigs. A tapered spar is not built to take huge compression loads at the
mast head. OTOH they can easily be built to take a heck of a torsion
load at the gooseneck... some have solid struts supporting the mast just
at or just below the gooseneck.

Your statements about rigid vangs are like the yokel who was shown a
picture of a giraffe and said "there cain't be no such anny-mal."

DSK